Last frost date in Mankato, MN
In Mankato, the last spring frost comes around April 30 in an average year. Wait until May 12 if you want 90% odds of no more frost. The first fall frost usually arrives about October 9, which leaves 161 frost-free days. An early freeze before September 25 happens one year in ten.
- Safe after (10% risk)
- May 12
- Average first frost
- Oct 9
- Frost-free season
- 161 days
- Hard freeze (28°F) ends
- Apr 19
No frost in the next 7 nights
Later than usual: the average first frost here is October 9.
National Weather Service forecast, updated Oct 22, 12:57 UTC
- ThuOct 2255°
- FriOct 2360°
- SatOct 2449°
- SunOct 2543°
- MonOct 2640°
- TueOct 2740°
- WedOct 2842°
Planting calendar for Mankato
Windows count forward or back from the average frost dates above. Click a crop for dates across Minnesota.
TomatoesMay 7–May 21
PumpkinsMay 14–May 28
SunflowersApr 30–May 21
CucumbersMay 14–May 21
CornMay 7–May 21
Sweet potatoesMay 21–Jun 4
WatermelonMay 14–May 28
Green beansMay 7–May 28
ZucchiniMay 7–May 21
OkraMay 21–Jun 4
PeppersMay 14–May 28
BasilMay 7–May 21
Butternut squashMay 7–May 21
CantaloupeMay 14–May 28
EggplantMay 14–May 28
PotatoesApr 2–Apr 16
OnionsMar 19–Apr 9
CarrotsApr 9–May 14
LettuceApr 16–May 7
BroccoliApr 2–Apr 16
BeetsApr 2–May 14
PeasMar 19–Apr 2
CabbageApr 2–Apr 16
RadishesMar 26–May 7
Brussels sproutsApr 16–Apr 30
SpinachMar 19–Apr 9
CilantroApr 16–May 7
KaleApr 2–Apr 16
Collard greensApr 2–Apr 16
TurnipsApr 2–Apr 16
DillApr 30–May 14
CeleryMay 7–May 14
CauliflowerApr 16–Apr 30
LeeksApr 16–Apr 30
Swiss chardApr 16–May 14
ParsleyApr 16–May 7
Tulip bulbsSep 25–Oct 30
GarlicSep 18–Oct 23
Daffodil bulbsSep 11–Oct 23
StrawberriesApr 2–Apr 16
AsparagusApr 2–Apr 16Frost probabilities
| Threshold | Spring, 90% chance later | Spring, 50% | Spring, 10% | Fall, 10% chance earlier | Fall, 50% | Fall, 90% |
|---|---|---|---|---|---|---|
| Light frost, 32°F | Apr 16 | Apr 30 | May 12 | Sep 25 | Oct 9 | Oct 22 |
| Hard freeze, 28°F | Apr 6 | Apr 19 | May 2 | Oct 4 | Oct 20 | Nov 1 |
Read the spring 10% column as the date after which only one year in ten still gets frost. That is the safer date for tomatoes, peppers and basil.
Where these numbers come from
NOAA station Mankato (USC00215073) sits 2.6 miles from the center of Mankato at 850 feet. Its averages cover 1991 to 2020. Low spots, valleys and open fields can keep getting frost a week or two after the station stops; city centers and lakeshores usually get less of it.
Questions
When is the last frost in Mankato, MN?
The average last frost date in Mankato is April 30, based on NOAA 1991–2020 climate normals. There is a 10% chance of frost after May 12.
When is the first frost in Mankato?
The first frost in fall usually comes around October 9. One year in ten it arrives before September 25.
How long is the growing season in Mankato?
About 161 days between the average last and first frost.
When should I plant tomatoes in Mankato?
Plant tomato seedlings outside from May 7 to May 21. Start seeds indoors six to eight weeks earlier.
Nearby in Minnesota
- FaribaultMay 5
- OwatonnaMay 5
- NorthfieldMay 5
- Prior LakeApr 23
- ChaskaMay 5
- ShakopeeApr 23
- LakevilleApr 27
- SavageApr 23
- ChanhassenApr 30
- FarmingtonApr 27
- Eden PrairieApr 23
- BurnsvilleApr 27